An automated laboratory procedure for the determination of several environmentally important organotin compounds is set out in detail in a paper presented and published at the Proceedings of the Organotin Symposium of the Oceans 86 Conference and Exposition, Washington, D.C., Sept. 23-25, 1986. This automated analysis utilizes hydride derivatization directly in seawater yielding volatile mono-, di- and tributyltin species which can be concentrated sufficiently to assure their detection. This analysis apparatus is schematically shown in FIG. 1 of the drawings for the speciation of trace organotin compounds. The method employs hydride derivatization directly in seawater yielding the volatile mono-, di- and tributyltin hydride species. The tin hydrides from a one liter sample are concentrated in a cryogenic trap "a" coupled to a liquid nitrogen source "b". Eletrothermal heating of trap "a" volitolizes the hydride compounds in a hydrogen flame burner 10 enabling the detection of the compounds of interest via an atomic absorption spectrophotometer "c". A controller "d" relies on an IBM-PC or compatible PC equipped with interface electronics for I/O control. Software is written in the Poly FORTH language which provides a multiuser multitasking environment.
This computer control, among other things, controls an analytical section including a reagent addition unit "e". A pump "f" draws a seawater sample at "In", and transfers the sample into a hydride reaction vessel "h". Appropriate valving and the addition of helium channels the reaction product to trap assembly "a" which is under control of computer "d".
Atomic absorption spectrophotometer "c" is a standard Buck instruments model 200 and has a sensitivity that is adequate for most butyltin monitoring requirements. Hydrogen and air were added to the concentrated reaction product coming into the burner and the appropriate analysis was made in accordance with the established procedures for the spectrophotometer. A thorough understanding of the operation of this analytical apparatus is set forth in the above cited publication.